J/AJ/149/110 Radial velocities of 47 Oph (Wang+, 2015)
The three-dimensional orbit and physical parameters of 47 Oph.
Wang X., Hummel C.A., Ren S., Fu Y.
<Astron. J., 149, 110 (2015)>
=2015AJ....149..110W 2015AJ....149..110W
ADC_Keywords: Binaries, spectroscopic ; Radial velocities ; Positional data
Keywords: astrometry - binaries: spectroscopic - stars: fundamental parameters -
stars: individual: 47 Oph
Abstract:
Although 47 Oph has been shown to be a binary with a period of ∼27days
using both spectroscopic and interferometric techniques, only a
preliminary orbit has been obtained in the previous work due to the
shortage of high precision measurements. Since 1997, new spectroscopic
and interferometric measurements have been obtained with much higher
precision by the spectrograph of the 2.16m telescope at Xinglong
station and the Navy Precision Optical Interferometer, respectively.
Combining all of the measurements, a three-dimensional orbit is
obtained with high precision in this work. Thus, the component masses
are calculated to be 1.50±0.06 and 1.34±0.06M☉,
respectively. The orbital parallax is 32.6±0.6mas, which is
consistent with the Hipparcos parallax. With the known apparent
magnitudes and color indices of the components, the derived
luminosities are 7.80±0.36 and 3.41±0.25L☉. The estimated
radii of the components are 2.06±0.07 and 1.36±0.06R☉.
Finally, the evolutionary status of the components are investigated
with the help of a stellar evolution model.
Description:
The Mark III Stellar Interferometer was operated on Mt. Wilson from
1990 to 1992. 47 Oph was observed during six nights on a baseline
between the north D and south F stations (27m), recording fringes in
three narrowband channels (∼25nm) centered at 500, 550, and 800nm. The
data were reduced as described by Mozurkewich et al.
(1991AJ....101.2207M 1991AJ....101.2207M). The results are given in Table 1.
To obtain precise radial velocity measurements (see Table 4),
high-resolution spectral observations of 47 Oph have been carried out
since 2011. At the outset, the Coude Echelle Spectrograph (CES)
mounted on the 2.16m telescope at Xinglong station was used. We chose
the blue arm and medium focal length camera, a configuration covering
a wavelength range of 3300-5800Å with a spectral resolution
(R=λ/Δλ) of about 80000. After 2012 July, the HRS
covering the wavelength region of 4030-10250Å installed on the same
telescope came into use. The slit width was set to 0.19mm,
corresponding to a spectral resolution of ∼45000 around 5500Å.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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17 26 37.88 -05 05 11.7 47 Oph = HIP 85365 (P=26.27565)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 60 22 Observation and result log for 47 Oph
table4.dat 79 64 Radial-velocity measurements of 47 Oph
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See also:
B/sb9 : 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix+ 2004-2014)
J/ApJS/180/117 : MK classifications of spectroscopic binaries (Abt, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Date UT date of observation
8- 15 F8.3 yr Year [1990/2003] Fractional Julian year of observation
17- 20 I4 --- Nv [15/1349] Number of measured visibilities
22- 26 F5.2 mas Sep [2.98/11.4] Derived separation ρ
28- 33 F6.2 deg PA [0/360] Derived position angle θ
35- 38 F4.2 mas eMaj Major axis of the 1σ uncertainty ellipse
40- 43 F4.2 mas eMin Minor axis of the 1σ uncertainty ellipse
45- 49 F5.1 deg ePA Position angle of the uncertainty ellipse φ
51- 55 F5.2 mas O-C1 Deviation of the fitted relative binary
separation from the model values O-Cρ
57- 60 F4.1 deg O-C2 Deviation of the fitted relative binary
position angle from the model values O-Cθ
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d JD Julian Date (JD-2400000)
11- 15 F5.1 km/s RV1 [-26.7/81.6] Primary radial velocity
17 A1 --- f_RV1 [a] Radial velocity data not used to fit the orbit
19- 21 F3.1 km/s e_RV1 1σ uncertainty in RV1
23- 27 F5.1 km/s O-C1 The primary (O-C) value
29- 33 F5.1 km/s RV2 [-82.6/30]? Secondary radial velocity
35 A1 --- f_RV2 [a] Radial velocity data not used to fit the orbit
37- 39 F3.1 km/s e_RV2 ? 1σ uncertainty in RV2
41- 46 F6.2 km/s O-C2 ? The secondary (O-C) value
48- 79 A32 --- Ref Reference
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 23-Mar-2015